Hammer-drill.



W. PMSLLWI'IZ.l

HAMMER DRILL. I APPLICATION FILED JUNE l5, 1909.

UNITED sTATzs PATENT carica.

PRELLWITZ, EASTON, PENNSYLVANIA, ASSIGNOR T0 INGERSDLL-RANDlA COMPANY, QI' NEW' YORK, vN. Y., A CORPORATION 0F NEW JERSEY.

HAMMEBPDMLL.

Specification of Letters Patent.

Patented Mar. 25, 1913.

Original vapplication.mail February 15, 1909, Serial No. 428,112. Divided and this applcationinled June A 15, 1909. Serial Nn'. 502,254. v

To all whom t mayconcem:

Be it known that I, WILLIAM PRELLWITZ, a citizen of the United States, and, resident ofEaston, in the county of Northampton and State of Pennsylvania, have invented a new and useful Improvement in Hammer- Drills, of which the following is a specification. i

rllhis invention relates to hammer drills andfhas for its object to provide a novel .construction at thefront end of the drill which will beparticularly well adapted for feeding fluid under pressure to a hollow dri-ll steel of common form, fluid-tight connectionsbeing provided for the -pressure fluid 4feeding chamber and also between the drill steel'and its chuck.

In the accompanying drawings, Figure 1 represents the front end of a'hammer drill embodying the invention, vthe parts being shown partially inside elevation and partially in longitudinal central section; the drill steel being shown in dotted lines in its operative position, Fig.'2 is a detail lon-l gitudinal central section at the front end' of the drill showing' the drill steel in full lines in its position within its chuck,-Fig. 3

is a front end view of the drill with the drill steel removed and a portion of the handle broken away, and Fig. 4 is a transverse section taken in the plane of the line A-A of Fig. 1, looking in the direction of the arrows. I

.The hammer drill cylinder is denoted by l.4 It is provided with `the usual pistonr hammer 2 whichv is fitted to reciprocate in the cylinder chamber 3. The hollow front head 4 is rigidly secured to thefront end of the cylinder 1, as, for instance, by being screwed. thereon and locked against movement by a clamp ring `5. v-

The drill steel receiving 'chuck is denoted by 6, which chuck extends inwardly through the outer end of the front head 4 and it is locked to the front head by any suitable,

means, such, Ifor instance, asby across p in 7. The socket 8 in the chuck for the drlll steel extends entirely through the chuck and opens into a pressure fluid feeding chamber' 9 Within a tube 10 interposed between the front end ofthe Acylinder 1 and an inner shoulder l1 of the front head located 'a short distance bevond the inner end of the chuck 6.

The head 12 of the anvil block is located within the/pressure fluid feeding chamber 9 and its shank 13 extends rearwardly through the tube 10 and reduced front end 14 of the cylinder 1' into the chamber 3 in position to bestruck' by the hammerpiston 2. This tube 10 is provided with an interior annular rib 15 which forms a shoulder against which the inner end of the head ,12. of the anvil block abuts.

The front head 4 is provided with a transverse hole 16 in alinernent with a transverse hole 17 in the tube 10 for permitting the` attachmentvof a pressure fluid sup ly pipe'l 18 forfeeding the pressure lui tothe chamber 9.

The head 1 2 of the anvil block is providedv with an axially arranged duct 19 vopening through its front end in alinen'ient with the bore 20 of the hollow drill steel with the chamber 9 at all times through a branch duct 22.

A cup washer 23 is interposed between the tube V10 and the inner end of the chuck 6 to form a fluid tight packing at this point, the circumferential flange '21 of which washer is seated in an annular recess 25 in the front end of the tube 10. A cup washer' 26 is interposed between the tube 10 and the shank 13 of the anvil block to form a fluid tight packing at this point, the circumferential flange 27 of which washerl `being seated in an annular recess 28 in the inner end of the tubelO. I

A fluid tight packing is formed between the drill steel and its chuck at the outer end of the chuck, as follows z-An elastic 'cup shaped washer 29 has a normally contracted bore of the s me cross sectional shape as the drillstee .and the socket 'of thel chuck, the circumferential flange 30 of Which cup washer is Secured to a rigid protectin rin 31, which protecting ringis provi ed with a flaring bore 32 of the saine` crosssectional' form as the drill steel'. The Y washer 29 andl ring 31 areshown as secured together -.b interlocking their adiacent` ends whereby `t 'e Ering 'not onlyacts as a protector for thewasher to protect it from injur when the drill steel is inserted into the ciuck but also is utilized for the insertion andremoval of the said cup washer.`

The normally contracted bore 'of the elastic` cup-washer 29 is preferably formed by tapering the bore from the front to thel rear end of the Washer. This cupA Washer '29 and a portion of its protecting ring 31, are seated in a stepped recess 33 in the outer end of the chuck 6 and are removably held in such position =in the present instance by providing a screw capl having a central hole -35 for the reception of the drill steel.'

It will be seen that by providing a con` struction as herein shown and described,

the pressure fluid feeding chamber 9 is rendered Huid tight and also that a lluid tight connect-ion is provided bet-Ween the drill steel and its chuck. Furthermore, it will be seen that the 'parts may be very quickly assembled and disassembled for permitting the renewal of the packings or other parts and also that the device is applicable for use in connection With the common form i of drill steel.`

By providing the elastic cup Washer at the mouth of the chuck with a protecting ring'of rigid material, it will be seen that the Washer is protected :trom injury when the drill steel is inserted into the chuck.

of which this present application is a division.

l. A drill steel receiving chuck and a lluid-tight packing for the steel comprising an elastic Washer and a rigid protecting ring having their adjacent ends interlocked.

2. A,dr1ll steel receiving chuck and a fluid-tight packing for the steel comprising an elastic Washer and a rigid protecting ring having their adjacent ends interlocked the washer having a normally contracted bore.

3. A drill steel receiving chuck and a {luid-tight packing for the steel comprising an elastic Washer and a rigid protecting ring having their adjacent ends interlocked, the protecting ring having a flaring bore.

fl. A drill steel receiving chuck and a fluid-tight packing for the steel comprising an lelastic washer and a rigid protecting ring having their adjacent ends interlocked, the elastic Washer having a normally contracted bore and the protecting ring having a flaring bore.

Injtestimony, that I claim the lforegoing as my invention, I have signed my name in presence of two Witnesses, this 12th day ot June 1909.

WILLIAM PRELLWITZ. Witnesses:

F. GEORGE BARRY, C. S. SUNDGREN. 

